161 research outputs found
Phylogenetic studies in Gnaphalieae (Compositae): The genera Phagnalon Cass. and Aliella Qaiser & Lack
130 p., tablas, mapas, fot. -- Se corresponde con el capítulo 7 del libro Recent Advances in Pharmaceutical Sciences IIIThe precise generic delimitation of Aliella and Phagnalon, and their closest relatives within the Gnaphalieae are discussed in this review. Among the main results obtained, we have found that the genera Aliella and Phagnalon are nested within the “Relhania clade” and Anisothrix, Athrixia and Pentatrichia are their closest relatives. Macowania is also part of the “Relhania clade”, whereas the subtribal affinities of Philyrophyllum lie within the “crown radiation clade”. The monophyly of Aliella and Phagnalon is not supported statistically. In addition, Aliella appears to be paraphylethic in most of the analyses performed. The resulting phylogeny suggests an African origin for the ancestor of Aliella and Phagnalon and identifies three main clades within Phagnalon that constitute the following natural groups on a geographic basis: (1) the Irano-Turanian clade; (2) the Mediterranean-Macaronesian clade; and (3) the Yemen-Ethiopian clade. Some endemics to Yemen and Ethiopia appeared merged in the Mediterranean-Macaronesian clade, providing new evidence of the phytogeographical links between Macaronesia, Eastern Africa and Southern Arabia. Incongruities between the chloroplast and nuclear molecular data and the lack of resolution in some clades may indicate that hybridization could have played an important role in the evolution and diversification of both Phagnalon and Aliella.This work has been partly financed by the Spanish government (REN2002-04634-C05-01, CGL2004-04563-C02-01/BOS) and the Catalan government (“Ajuts a grups de recerca consolidats” 2009/SGR/00439).Peer reviewe
Phylogeography of western Mediterranean Cymbalaria (Plantaginaceae) reveals two independent long-distance dispersals and entails new taxonomic circumscriptions
The Balearic Islands, Corsica and Sardinia (BCS) constitute biodiversity hotspots in the western Mediterranean Basin. Oligocene connections and long distance dispersal events have been suggested to cause presence of BCS shared endemic species. One of them is Cymbalaria aequitriloba, which, together with three additional species, constitute a polyploid clade endemic to BCS. Combining amplified fragment length polymorphism (AFLP) fingerprinting, plastid DNA sequences and morphometrics, we inferred the phylogeography of the group and evaluated the species' current taxonomic circumscriptions. Based on morphometric and AFLP data we propose a new circumscription for C. fragilis to additionally comprise a group of populations with intermediate morphological characters previously included in C. aequitriloba. Consequently, we suggest to change the IUCN category of C. fragilis from critically endangered (CR) to near threatened (NT). Both morphology and AFLP data support the current taxonomy of the single island endemics C. hepaticifolia and C. muelleri. The four species had a common origin in Corsica-Sardinia, and two long-distance dispersal events to the Balearic Islands were inferred. Finally, plastid DNA data suggest that interspecific gene flow took place where two species co-occur
Amplificación cruzada de microsatélites en el género Centaurea (Compositae).
11p. Fotog. en color. Tablas.[EN] Microsatellites are widely used for population
genetic studies although the development of these species-specific markers is costly and time-consuming. One strategy for
saving time and money is the use of markers developed for one species (source species) in a different species (target species).
This is known as cross-amplification. In the present work, two sets of microsatellites are used to test their transferability to six
narrow endemic Centaurea species: i) 16 nuclear loci previously published for three congeneric species and ii) 10 universal
chloroplast markers designed from Nicotiana tabacum sequences. Seventeen of the 26 markers tested were transferable and
14 of them were also polymorphic and therefore useful for future works. Nuclear markers were more variable and thus more
informative than chloroplast markers. Interspecific amplification performed better for the nuclear loci developed for different
Centaurea species than for the universal chloroplast markers developed for Nicotiana tabacum. Likewise, transferability was
more successful for the species from sect. Phalolepis than for sect. Lepteranthus. Therefore, our results support the idea that
the success of the cross-amplification is influenced by the evolutionary distance between the target and the source species.[ES] Los microsatélites se usan habitualmente
en estudios de genética de poblaciones aunque su desarrollo es un proceso caro y largo dada su elevada especificidad. Una
estrategia que permite ahorrar tiempo y dinero es la llamada amplificación cruzada que consiste en amplificar el DNA de
una especie determinada (especie objetivo) usando marcadores que han sido diseñados para una especie diferente (especie
fuente). En este trabajo se ha realizado un ensayo sobre amplificación cruzada usando seis endemismos del género Centaurea
y dos conjuntos de microsatélites: i) 16 marcadores nucleares desarrollados para tres especies congenéricas y ii) 10 marcadores
cloroplásticos universales diseñados para Nicotiana tabacum. Diecisiete de los 26 marcadores evaluados resultaron
transferibles, de los cuales 14 fueron polimórficos siendo así útiles para futuros trabajos. Las regiones nucleares se mostraron
más variables y por lo tanto más informativas que las cloroplásticas. La amplificación cruzada funcionó mejor para los
marcadores nucleares específicos de Centaurea que para los cloroplásticos universales específicos de Nicotiana tabacum.
A su vez, se obtuvo mejor resultado para las especies de la sección Phalolepis que para las de la sección Lepteranthus. En
consecuencia, nuestros resultados apoyan la idea de que el éxito de la amplificación cruzada está estrechamente ligado a la
distancia evolutiva entre especie fuente y especie objetivo.Financial support from the Spanish MICINN (Project
CGL2007-60781 and CGL2010/18631) and the Generalitat
de Catalunya (Ajuts a Grups de Recerca Consolidats 2009/
SGR/00439-GREB) is gratefully acknowledged.Peer reviewe
“Muntanyes i refugis”: investigadors de l’IBB publiquen un estudi genètic sobre endemismes de les muntanyes de Grècia
Noticia publicada en la web institucional del Instituto Botánico de Barcelona el 5 de noviembre de 2015 -- Disponibles PDFs en español y catalán y capturas de pantalla de la noticia en la web.Peer reviewe
Systematics and evolution of the needle grasses (Poaceae: Pooideae: Stipeae) based on analysis of multiple chloroplast loci, ITS, and lemma micromorphology
27 p.We conducted a molecular phylogenetic study of the tribe Stipeae using nine plastid DNA sequences (trnK-matK, matK, trnH-psbA, trnL-F, rps3, ndhF, rpl32-trnL, rps16-trnK, rps16 intron), the nuclear ITS DNA regions, and micromorphological characters from the lemma surface. Our large original dataset includes 156 accessions representing 139 species of Stipeae representing all genera currently placed in the tribe. The maximum likelihood and Bayesian analyses of DNA sequences provide strong support for the monophyly of Stipeae; including, in phylogenetic order, Macrochloa as remote sister lineage to all other Stipeae, then a primary stepwise divergence of three deep lineages with a saw-like (SL) lemma epidermal pattern (a plesiomorphic state). The next split is between a lineage (SL1) which bifurcates into separate Eurasian and American clades, and a lineage of three parts; a small Patis (SL2) clade, as sister to Piptatherum s.str. (SL3), and the achnatheroid clade (AC). The AC exhibits a maize-like lemma epidermal pattern throughout. AC consists of a core clade of Austral-Eurasian distribution and a “major American clade” of North and South American distribution. The base chromosome number for Stipeae is somewhat ambiguous but based on our survey it seems most likely to be x = 11 or 12. Our phylogenetic hypothesis supports the recognition of the following genera and groups (listed by region): Eurasia—Achnatherum, “Miliacea group”, “Neotrinia” (monotypic), Orthoraphium (monotypic), Patis (also 1 from North America), Piptatherum s.str., Psammochloa (monotypic), Ptilagrostis, Stipa, “Timouria group”, and Trikeraia; Mediterranean—Ampelodesmos (monotypic), Celtica (monotypic), Macrochloa (monotypic), and “Stipella-Inaequiglumes group”; Australasia —Anemanthele (monotypic), and Austrostipa; North America (NA)—“Eriocoma group”, Hesperostipa, Oryzopsis (monotypic), Piptatheropsis, “Pseudoeriocoma group”, and “Stillmania” (monotypic); South America—Aciachne, Amelichloa (also NA), Anatherostipa (s.str.), Jarava (polyphyletic), Lorenzochloa, Nassella (also NA), Ortachne, Pappostipa (also NA), and Piptochaetium (also NA). Monophyly of Phaenospermateae including Duthieinae is demonstrated, and its inclusion within or treatment as sister to Stipeae is rejected.Peer reviewe
ISOLATION AND CHARACTERIZATION OF NOVEL MICROSATELLITE MARKERS FOR ARCTIUM MINUS (COMPOSITAE)
[EN] Premise of the study: Microsatellite primers were developed for the invasive plant Arctium minus to investigate the effects of
facultative self-pollination and the biannual habit on population genetic structure, as well as the colonization of the Americas by this Eurasian species. Methods and Results: Sixteen di- and trinucleotide microsatellite loci were identifi ed in six populations. The number of alleles
per locus ranged from one to 10, observed heterozygosities ranged from 0.000 to 0.897, and the mean value of F IS was 0.316.
Conclusions: These results indicate the utility of these loci in future studies of population genetics in A. minus .Peer reviewe
Speciation and genetic diversity in Centaurea subsect. Phalolepis in Anatolia
14 p., mapas, tablasMountains of Anatolia are one of the main Mediterranean biodiversity hotspots and their richness in endemic species amounts for 30% of the flora. Two main factors may account for this high diversity: the complex orography and its role as refugia during past glaciations. We have investigated seven narrow endemics of Centaurea subsection Phalolepis from Anatolia by means of microsatellites and ecological niche modelling (ENM), in order to analyse genetic polymorphisms and getting insights into their speciation. Despite being narrow endemics, all the studied species show moderate to high SSR genetic diversity. Populations are genetically isolated, but exchange of genes probably occurred at glacial maxima (likely through the Anatolian mountain arches as suggested by the ENM). The lack of correlation between genetic clusters and (morpho) species is interpreted as a result of allopatric diversification on the basis of a shared gene pool. As suggested in a former study in Greece, post-glacial isolation in mountains would be the main driver of diversification in these plants; mountains of Anatolia would have acted as plant refugia, allowing the maintenance of high genetic diversity. Ancient gene flow between taxa that became sympatric during glaciations may also have contributed to the high levels of genetic diversity.This work was supported by the Spanish Ministerio de Ciencia e Innovación [project CGL2010/18631] and Generalitat de Catalunya [Ajuts a Grups de Recerca Consolidats 2014-SGR514-GREB]Peer reviewe
Influence of the Quaternary Glacial Cycles and the Mountains on the Reticulations in the Subsection Willkommia of the Genus Centaurea
Late Neogene and Quaternary climatic oscillations have greatly shaped the genetic structure of the Mediterranean Basin flora, with mountain plant species tracking warm interglacials/cold glacials by means of altitudinal shifts instead of broad latitudinal ones. Such dynamics may have enhanced population divergence but also secondary contacts. In this paper, we use a case example of subsection Willkommia of Centaurea (comprising three narrowly distributed endemic species, Centaurea gadorensis, C. pulvinata, and C. sagredoi) to test for reticulate evolution and recurrent hybridizations between nearby populations. For this, we combine analyses of genetic diversity and structuring, gene flow and spatial correlation, and ecological niche modeling. Our results support the contention that the current genetic structure of the three species is the result of historical gene flow at sites of secondary contact during the glacial periods, followed by isolation after the retraction of populations to the middle-upper areas of the mountains during the interglacial periods. The extent and direction of the gene flow was determined largely by the location of the populations on mountainsides oriented toward the same valley or toward different valleys, suggesting the intermountain valleys as the areas where secondary contacts occurred
Micromorphology and fatty acid composition of the cypselae of Xeranthemum cylindraceum Sm. (Asteraceae, Cardueae)
The paper presents micromorphology of the cypselae of Xeranthemum cylindraceum as revealed by scanning electron microscopy (SEM) and their fatty acid composition as determined on a gas chromatograph coupled with a flame ionisation detector (GC-FID). The cypselae are densely hairy, straight, ribbed, narrowly obconical to obovoid. Micromorphological features are as follows: striate-rugose surface; adaxial detachment area; asymmetrical carpopodium; presence of biseriate, nonglandular, shortly forked twin hairs; and absence of a pericarp crown. The pappus is paleaceous, homomorphic, uniseriate, persistent, and with several wide, scarious, subulate, and apically pinnulate bristles of variable length. Out of 12 fatty acids detected, nine (88.57%) are identified, ranging from palmitoleic (C16:1) to behenic (C22:0) acids. Oleic acid is dominant (55.24%). Unsaturated fatty acids are predominant in the oil (75.02%). The composition of fatty acids in cypselae of the given species is here reported for the first time. The taxonomic value of the analysed characters is briefly discusse
African mountain thistles: generic delimitation problems analyzed with NGS
Póster presentado en el III Simposio Anual de Botánica Española celebrado en el Institut Botànic de Barcelona, 25-26 de noviembre de 202
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